SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '28168227c38eb0f41a2685e3ce44a9feafc88e1c8bdab79a1bfa346d9d48ec2d' 
  AND token = 'yIp6lTxeQRKO+qUW8kbccDbqLQF93Hy37o0KFzTCeNU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}